This invention relates to an improved automobile engine having directional auxiliary intake injection adjacent the spark gaps for enhancing combustion, reducing emissions, etc.
In the idling or light-load operation of a conventional automobile engine, the degree of throttle valve opening is small and the amount of gas drawn in is small. Thus, the speed of the gas mixture flowing into a cylinder during a suction stroke is low and its swirl into the cylinder is weak. Consequently, its swirl in the cylinder is also weak at the time of ignition which usually takes place in a final part of a compression stroke, and the ignitability and combustibility thereof is poor. In order to secure the safe operation of an engine, it is thus necessary to supply a gas mixture that has an air/fuel ratio smaller than that of a mixture supplied during high-load operation. This increases the fuel cost and the production of CO and HC in the exhaust gas due to the incomplete combustion of the dense gas mixture. It has recently been proposed that a gas mixture having a ratio smaller than a theoretical one be used to decrease the CO, HC and NOx emission in the engine exhaust. It has also been proposed that part of the exhaust gas be extracted from the engine exhaust system and fed back into the gas mixture to be burned to decrease the NOx in the exhaust gas. When either of the above techniques is used, however, the drivability of the engine, especially during idling and light-loads, is decreased because the ignitability and combustibility of the gas mixture in such cases is poor. Thus, the fuel cost is increased.